This invention relates generally to systems for measuring forces and more particularly, to a system which mesures forces applied by a limb of a living being in a plurality of directions using only a single force transducer.
Cumulative trauma disoders are being reported with increasing frequency in industrial settings. One such cumulative trauma disorder is Carpal Tunnel Syndrome, which is characterized by decreased median nerve conduction velocities; decreased sensation in the palm, thumb, index, or middle fingers; decreased strength; pain; and swelling. Inflammation of tendons in the wrist resulting in swelling can compress the median nerve causing the resultant changes in sensation, strength and pain. One reason for the increase in the reporting of cumulative trauma disorders, particularly Carpal Tunnel Syndrome is that the increasing mechanization of industry requires workers to perform more repetitive work. It is the repetitive nature of the work which contributes to the cumulative trauma disorders.
There is a need for a reliable, portable, and inexpensive apparatus and system for measuring muscle force for assessing maximal force, percent of maximal force, and force curves during wrist and forearm motions. The force measures are then correlated with the forces required in specific work tasks, lifestyle, psycho-social factors, and other physiological factors which contribute to the manifestation of Carpal Tunnel Syndrome.
In addition to ascertaining whether one has a cumulative trauma disorder, there is also a need for a system which assists in identifying persons at higher risk for developing such disorders, particularly Carpal Tunnel Syndrome. Preferably, such a system should be useful in the acquisition of information pertaining to:
1. Maximal and submaximal wrist forces, including flexion, extension, radial deviation, and ulnar deviation; PA0 2. Maximal and submaximal forearm forces, including supination and pronation; PA0 3. Wrist and hand nerve conduction velocity studies; PA0 4. Correlation of the foregoing measures with wrist and hand sensation, range of motion, and flexibility; PA0 5. Correlation of the foregoing measures with the information acquired by the Carpal Tunnel Syndrome employee assessment system, which includes information such as: PA0 (1) first coupling the limb of the living being to a first flexible line (e.g., cable); PA0 (2) moving the limb of the living being so as to apply a tensile force onto the first flexible line; PA0 (3) transmitting the tensile force via the first flexible line to a transducer; and PA0 (4) producing a signal responsive to the tensile force.
a. personal demographic characteristics; PA1 b. current work tasks and past work tasks; PA1 c. prior medical conditions and injuries; PA1 d. current symptons possibly associated with work tasks; PA1 e. employee perception of pain; PA1 f. lifestyle patterns; PA1 g. current medical conditions and associated medications; PA1 h. past and present exercise routines; PA1 i. hobbies and outside of work activities; and PA1 j. work satisfaction.
In order to identify work site-related factors which may contribute to cummulative traumma disorders or aggravate existing symptons associated with Carpal Tunnel Syndrome, it may be useful to compare wrist and forearm forces required to perform a work task with the employees' ability to generate maximal and submaximal wrist and forearm forces. It may additionally be useful to compare, on specific work tasks, force curves of experienced or skilled workers, in contrast to those of new employees.
It is, therefore, and object of this invention to provide a simple and inexpensive system for measuring multiple types of forces and torques producible by a limb of a living being.
It is another object of this invention to provide a system which can readily produce signals repesentative of the various forces or loads which can be applied by a limb of a living being, the forces being readily correlatable to one another.
It is also an object of this invention to provide a method and apparatus for measuring and evaluating the strength and ability of movement of a limb or upper extremity of a living being wherein the data is easily supplied to a computer.
It is a further object of this invention to provide a limb strength and mobility monitoring system which is easily transportable to a work place.
It is additionally an object of the invention to provide a force mesurement system for assessing the nature and extent of cumulative trauma disorders, which easily can be calibrated.
It is yet a further object of this invention to provide a strength measurement system which can measure grip strength and finger strength.
It is also another object of this invention to provide a dynamometer system which can perform all of the necessary strength tests asssociated with the forearm, wrist, and hand.